The radar is very annoying : it show only a tiny portion of the map, and you have to move the radar window to see other portions of the map, which is quite counter-intuitive. The radar should follow at least camera position and zoom (and if possible, camera orientation in the xy plane). This way you could zoom out and see as much on the radar as you can see on the map.

Also, you have to stick the radar to the edge of the screen to see the very edge of the map. If you don't stick to the edge of the screen you won't see that alien on the edge of the map. There should be a gap around the map on the radar view.